Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: January 14, 2000
Publication Date: March 14, 2000
Citation: Freetly, H.C., Ferrell, C.L., Jenkins, T.G. 2000. Timing of realimentation of mature cows that were feed-restricted during pregnancy influences calf birth weights and growth rates [abstract]. Journal of Animal Science. 78(Suppl. 2):90. Technical Abstract: The objective was to determine the effect of feeding strategies that allowed weight loss followed by weight gain on the efficiency of feed utilization for calf production. The first treatment (H-H-H) was designed to maintain body condition score of mature cows at 5.5 from the second trimester until the subsequent breeding season. The second treatment (L-H-H) was designed such that cows lost body condition during the second trimester and regained it during the third trimester and were equal in weight and body condition scores at parturition to cows assigned to the H-H-H treatment. The third treatment (L-L-H) was designed so that cows lost body condition during the second trimester and gained body condition after 28 d of lactation so they would be equal to the other two treatments at breeding; 48 cows were assigned to each treatment. Total DM intake over the entire study did not differ between the H-H-H and L-H-H treatments but both were higher than the L-L-H treatment. Calf birth weight of the H-H-H treatment did not differ from those of L-H-H but both were greater than those of the L-L-H treatment. At 28 d H-H-H and L-H-H calves weighed more than the L-H-H calves but at 58 d of age there was no difference in calf BW among the treatments. The percentage of cows that were diagnosed pregnant at weaning with their next calf did not differ. These results suggest that weight cycling in mature beef cows is a viable management tool for reducing feed cost.